Workbench Design

While hunched over a messy project on my garage floor, I decided that what I really needed was a utility workbench, a bench with a metal top that would take a beating and save my nicer woodworking bench from getting dented and covered with grease. I just wasn't sure where to get the metal. After checking around, I found the answer at a local heating and air conditioning company.

Using a special bending tool, they were able to fold the edges of a large piece of sheet metal to fit over a piece of MDF that I wanted to use for the top. This created an extremely tough, durable worksurface. Check with a heating and air conditioning shop in your area for the same type of service.

The best part of this bench design is that it's easy to build. Using simple rabbet and dado joints, the different parts of the bench fit together like pieces of a jigsaw puzzle. In fact, you can build the basic bench in one weekend. Then drawers and a small storage unit with plastic bins can easily be finished up the following weekend.

Materials

Leg Pieces (8) 1-1/2 x 3 - 33

Sides (2) 21 x 21-1/4 - 3/4 MDF

Filler Strips (4) 3/4 x 3/4 - 12

Back (1) 21 x 63 - 3/4 MDF

Upper Back Stretcher (1) 1-1/2 x 3 - 60

Lower Back Stretcher (1) 1-1/2 x 21/4 - 63

Upper Front Stretcher (1) 1-1/2 x 3 - 63

Lower Front Stretcher (1) 1-1/2 x 3 - 63

Rails (7) 1-1/2 x 2-1/4 - 19-3/4

Shelf (1) 22 x 45-1/2 - 3/4

MDF Drawers & Top

Left Slide Panel (1) 18 x 19-3/4 - 3/4 MDF

Spacers (2) 2 x 18 - 3/4 MDF

Right Slide Panel (1) 18 x 22 - 3/4 MDF

Trim Strip (1) 1-1/2 x 1-1/2 - 15

Front/Backs (6) 3/4 x 3-1/2 - 14

Sides (6) 3/4 x 3-1/2 - 22

Bottoms (3) 14 x 21 - 1/2 Plywood

Narrow False Front (1) 4 x 15-3/4 - 3/4 MDF

Wide False Front (2) 51/4 x 15-3/4 - 3/4 MDF

Top Piece (1) 26-3/4 x 68 - 3/4 MDF Storage Unit

End Pieces(2) 5 x 12 - 3/4 MDF

Shelves (2) 5 x 38-1/2 - 3/4 MDF

Back (1) 4-1/2 x 38 - 1/4 Hardboard

Hardware

(3 pr.) 22" Drawer Slides

(8) #8 x 11/2" Rh Woodscrews

(9) #8 x 2" Fh Woodscrews

(47) #8 x 11/2" Fh Woodscrews

(12) #8 x 11/4" Fh Woodscrews

(3) 61/2" Drawer Pulls

(4) 23/4" x 23/4" Footpads (3/8"-thick)

There's one thing for sure about this utility bench. It won't budge when working on a project. That's because it's designed with a heavy base that adds mass and stability to the bench.

END ASSEMBLIES. The base starts out as two end assemblies connected by a back, see drawing. Each end assembly is made up of two legs and a side.

LEGS. The legs are thick posts made by gluing up two pieces of 1-1/2"- thick stock. To accept the sides (added later), I mounted a dado blade in the table saw and cut a long groove down the length of each leg. At this point, you can set the front legs aside. But the back legs still need some work. To create a notch for a stretcher and a shelf, start by cutting a wide dado in the inside face of each leg. You'll also need to rabbet the back inside edge of each leg to hold the back.

SIDE PANEL. After completing all four legs, you're ready to add the two sides. These sides are 3/4" MDF panels that fit into the grooves in the legs. After positioning the sides flush with the top of the legs, they're simply glued in place.

FILLER STRIPS. But this means that the part of the groove below the side is still exposed. So I glued a filler strip into each groove.

FOOTPADS. The bottom ends of the legs also need some attention. To prevent the end grain from wicking up moisture, I screwed a plastic footpad to each leg.

BACK. The next step is to add the back. It's a large MDF panel that connects the two end assemblies and keeps the bench from racking. After cutting the back to size, it's simply screwed to the legs.

STRETCHERS & RAILS. Now that the base was starting to take shape, I added a system of stretchers and rails to provide support for the top and shelf.

BACK STRETCHERS. I began with two long stretchers that span the back of the bench. An upper back stretcher is cut to length to fit between the two rear legs. But the lower back stretcher rests in the dadoes cut earlier in the legs, so it's 3" longer. The length isn't all that's different about the back stretchers--they're also different in width. The upper back stretcher is 3" wide. But I ripped the lower back stretcher to a width of 2-1/4". This way, when the stretcher is set in the dado, there will be 3/4" clearance above it--just enough to slide in the shelf. Before attaching the stretchers, there's one more thing to do. To accept the rails, you'll need to cut a groove down the length of each piece. Then just clamp the stretchers in place and secure them with screws driven through the back of the bench.

FRONT STRETCHERS. The upper and lower front stretchers are both cut to fit between the two end assemblies, so they're identical in length. And this time, they're the same width. Only here, the lower stretcher is rabbeted on the top inside edge to accept the shelf. As before, there's a groove in each of these stretchers to hold the rails. But what's different is the ends of the stretchers are rabbeted to fit around the legs. This way, the shoulders of the rabbets will help prevent the front of the bench from racking. Since the stretchers are quite long, I routed these rabbets using a simple jig.

RAILS. After screwing the front stretchers in place, the next step is to completing this workbench plan is to add the rails. There are seven rails altogether. The three rails that bridge the upper stretchers help support the top. And the four rails that span the lower section of this workbench design prevent the shelf from sagging when it's loaded with tools and supplies. The rails are designed to fit into the stretchers with a simple tongue and groove joint. The grooves are already cut in the stretchers. So all that's needed is to rabbet the end of each rail to form the tongue. Now it's just a matter of installing the rails. What works well here is to start by first setting the rails in rough position. (You'll need to angle the rails slightly to slip the tongues into the grooves.) Eventually, all the rails will be glued in place. But don't glue in the top and bottom rails on the left side of the bench yet. It's best to wait until after a slide panel is added later. It doesn't take much glue to secure the other rails. Just mark the final position of the rails and apply a small amount of glue in the groove. Then simply slide the rails into place.

SHELF. All that's left to complete the base is to add the shelf. It's just a piece of 3/4" MDF that rests on the lower stretchers and rails, see drawing above. Since the MDF is quite heavy, you don't need to secure the shelf. Just slide it into position so the shelf fills the exposed part of the dado in the back leg and butts against the side.

WORKBENCH DRAWERS. To provide plenty of storage space, there's a bank of three drawers on the left side of the bench. But I didn't start building them right away. First, I had to install a couple of large, flat panels to mount the drawer hardware.

LEFT SLIDE PANEL. I began with the left slide panel. It's a piece of 3/4" MDF that's cut to fit between the front and back legs. To fit the panel around the stretcher, you'll need to notch the upper front corner.

MOUNT SLIDES. After cutting the notch, I mounted the drawer slides. It's easier to do this now than having to reach inside the bench to do it later on. Before installing the panel, there's one thing to be aware of. The panel has to be flush with the inside face of the leg. Otherwise, when you open the drawers, they'll hit the leg.

SPACERS. To shim out the panel, I added two spacers. These are strips of 3/4" MDF that are sandwiched between the panel and the side of the bench.

INSTALL PANEL. Now you're ready to install the slide panel (and spacers). The trick is keeping these pieces from shifting out of alignment while you attach them to the side of the bench. This is especially important with the slide panel. To prevent the drawers from binding, the slides on this panel need to align with the slides on the right panel that's added next. To accomplish this, I cut a scrap of 3/4" MDF and used it as a temporary support to position the spacers and left slide panel. After securing the panel (and spacers) with screws, just remove the support.

RIGHT SLIDE PANEL. Now you can turn your attention to the right slide panel. It's the same height as the left slide panel. But it extends to the back of the bench, so it's longer. This means you'll need to notch both of the upper corners on this panel. Here again, it's best to mount the drawer slides before installing the panel. The bottom edge of this panel is secured by driving screws up through the shelf. (To do this, you may need to slide the "loose" rail on the bottom out of the way.) Then just glue this rail in its permanent location. To anchor the top part of the panel, I used a similar process. Start by checking that the panel is square to the shelf. Then glue the upper rail (the second loose rail) in place so it butts against the panel. When the glue dries, screw the panel to the rail.

TRIM STRIP. There's one last thing to do before making the drawers. That's to add a trim strip (N) that covers the exposed edge of the right slide panel. It's a piece of 1-1/2"-square stock (fir) that's rabbeted to fit the corner of the panel and then glued in place.

DRAWERS At this point, the groundwork for the drawers is complete. Now you can build the drawers to fit the opening in the bench. To keep things simple, all three drawers are identical in size. (One of the false fronts is smaller, but more about that later.)

DRAWER SIZE. There are several things to consider when sizing the drawers. First, the slides I used required a 1/2" clearance on each side. So the drawers are 15" wide (1" narrower than the opening). As for length, I made the drawers 22" long. The type of joinery also plays a part in the length of the drawer pieces. For these drawers, I used a locking rabbet joint. It's a simple joint, yet it provides plenty of strength. Once you've established the overall size of the drawers, cutting the pieces is just a matter of repetition. Start by cutting the fronts/backs and sides to final size. (I used 3/4"-thick pine.)

LOCKING RABBETS. Now it's time 6a. to cut the locking rabbet joints. To keep the drawers from pulling apart, tongues on the ends of the front and back fit into dadoes in the sides. What works best is to cut the dadoes first. Then sneak up on the thickness of the tongues by rabbeting the front and back pieces.

CUT GROOVES. Before assembling the drawers, you'll need to cut a groove near the bottom of each piece to hold a 1/2" plywood bottom. Then dry assemble the drawers to make sure the pieces fit.

SLIDES. After gluing and clamping the drawers together, you can mount the other half of the drawer slides. They simply wrap around the bottom edge of the sides. Now slide the drawers into the bench. This will make it easy to position the false fronts that are added next.

FALSE FRONTS. The false fronts are pieces of 3/4" MDF that are attached to the front of each drawer. One thing to note is they're not all the same size. I added a narrow false front to the top drawer and two wide false fronts to the two lower drawers. These pieces are sized to allow an 1/8" gap all the way around. After positioning the false fronts on the drawers, they're simply screwed in place. Finally, I mounted a heavy-duty pull to each drawer. The most noticeable thing about this bench top is its metal cover. But what you don't see is what's underneath the cover--a large top piece made from 3/4" MDf. It's this top piece that ensures a flat, stable worksurface that won't warp or twist with changes in humidity.

METAL COVER. But before cutting the top piece to size, it's best to have the metal cover in hand. Making this cover should be a routine process for a heating and air conditioning company. All you'll need to provide are the gauge (thickness) of the metal and the final size of the top piece. (My cover is made from 24 gauge metal and is sized to fit a 263/4" x 68" top.)

FOLDED EDGES. To avoid getting cut on a ragged burr (and to add rigidity to the metal), the edges of the cover are first folded underneath. Then these double-thick edges are bent at a 90-degree angle.

TOP PIECE. Once you have the cover back in the shop, you can cut the top piece to size. To "ease" the fit, I cut it 1/8" smaller than the inside dimensions of the cover. Also, A quick way to cover the sharp edge at each corner of the cover is to stick on a small strip of aluminum tape. Rounding over the top edges and softening the corners allows the cover to fit down over the top piece without wrinkling the metal. Before attaching the cover, you'll need to screw the top piece to the bench. Then simply secure the cover with strips of carpet tape to keep it from lifting off the top piece.

CORNERS. Finally, the corners of the cover still need some attention. That's because there's a "flap" at each corner with an exposed edge that's quite sharp. You can cover this edge with aluminum tape, see margin. Or for a more permanent solution, you may want to solder the corners, see the box below. Soldering the Corners It only takes a few minutes to solder the "flaps" on the corners of the metal cover.

SURFACE PREPARATION. To ensure a strong bond, the surface needs to be clean. But often, there's a greasy film on the metal. A bit of work with silicon-carbide sandpaper quickly removes the film. FLUX. The next step is to brush a thin layer of flux across the joint, see photo below left. The flux will make the solder flow smoothly into the joint.

HEAT METAL. After applying the flux, sweep a propane torch back and forth until the metal is hot. You'll know it's hot enough when you hold the solder against the metal and it begins to melt, see photo below right. Ideally, the solder should run evenly along the joint line. But most likely there will be some small gobs of solder that will need to be filed smooth. As an option, you may want to add a simple storage unit that sits on top of the bench, see photo at right. The storage unit is a handy way to store a few supplies or to organize small pieces of hardware. To hold the hardware, I used a number of plastic bins. It's best to purchase these bins before you get started. This will make it easy to determine the overall size of the storage unit. Note: I bought plastic storage bins at a local home center.

CONSTRUCTION. There's nothing complicated about the storage unit. It starts out as a pair of end pieces and two shelves made from 3/4" MDF. (I had pieces left over from the workbench.) The shelves fit in dadoes near the top of the end pieces. So when locating these dadoes, be sure there's enough clearance for the bins to slide in and out. Before assembling the storage unit, you'll need to cut a rabbet in the back edge of each shelf. This rabbet will accept a hardboard back that's added later.

ASSEMBLY. Now you're ready to assemble the storage unit. This is just a matter of gluing and clamping the shelves and end pieces together.

BACK. When the glue dries, it's time to add the back. It keeps the bins from sliding out the back of the storage unit. But more important, it adds rigidity that prevents the unit from racking. The back is a narrow strip of 1/4" hardboard that's cut to fit the opening between the shelves. Here again, it's simply glued and clamped in place.

APPLY FINISH. All that's left to complete the storage unit (and the workbench) is to apply a finish. To provide plenty of protection against dirt and moisture, I brushed on three coats of polyurethane. Of course, there were the usual drips and spills. But it didn't matter much--they landed on the metal cover, so I just wiped them off.